HOUSTON — The Iman Shumpert starting point guard experiment ended last night for the Knicks.

Toney Douglas was promoted to starting point guard last night for rookie Shumpert, but then played so poorly he got benched for third-string Jeremy Lin for the final 20 minutes of the Knicks’ 97-84 loss to the Rockets. One week ago, Lin was in the D-League rather than being wasted on the Knicks bench.

D’Antoni said the move also was made to get Shumpert, who had 11 points on 5 of 13 shooting, more time at small forward in the absence of Carmelo Anthony, who has shut it down for a couple of games to rest his assorted ailments. But D’Antoni gave an indication Douglas could stay there when Anthony gets back, pending the Baron Davis situation.

D’Antoni said he could not answer if Davis will be ready Tuesday at the Garden against Detroit for his debut. Douglas, after a good night in Miami on Friday, regressed, scoring just seven points (shooting 3 of 13 from the field), chucking five 3-pointers and making just one. He had four assists, but field to consistently penetrate and had three turnovers.

The bloom is off the Shumpert rose as for him being a point guard. It is understandable he has hit a wall, because the lockout schedule is extra- rough on rookies.

“Toney’s been playing the point guard better than Shump,’’ D’Antoni said before the game. “I think that today his best position will be the 2 or 3. He did a good job guarding LeBron James [Friday]. He’s learning the league. We’re learning where to play him. The 1 spot is not a natural one. It’s too much.’’

Shumpert, who had 11 points on 5 of 13 shooting, is now battling a couple of injuries, a sore left knee and a tweaked left ankle he hurt in Miami. Shumpert has been using a stimulator devise on his left knee, which is not the same one he sprained on Christmas.

D’Antoni said Shumpert has lost some of his early pop.

“Some of the brilliance of his athleticism has worn off a bit,’’ D’Antoni said. “For a rookie it’s a rude awakening to come in and play in so many gmes. His athleticism has come down a little bit because he has been banged up so it looks like physically he has struggled a bit.’’

Shumpert said he was not injury-prone at Georgia Tech, though he did have cramping episodes as he’s had here too.

“It’s probably the most banged up I’ve ever been during a season,’’ Shumpert said. “Usually, I don’t get hurt much. I expected it and just got to play through it. It’s all about being a rookie get used to it.’’

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D’Antoni said part of the offensive struggles are because the Knicks have not found Tyson Chandler (14 points, 11 rebounds) open inside, settling too much for 3-pointers.

“We missed Tyson over 25 times inside for layups,’’ D’Antoni said.

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The Rockets have beaten the Knicks seven straight times in Houston. … Despite ex-Knick lottery pick Jordan Hill’s double-double (14 points, 11 rebounds) last night, giving him four this season, Houston didn’t pick up his option for next season, and he will be a free agent. Hill had just two double-doubles in his first two seasons with Houston.